Rules of Thumb

http://www.kk.org/cooltools/
Rules of Thumb
Memorable estimates

"A rule of thumb is a homemade recipe for making a guess. It is an easy-to-remember guide that falls somewhere between a mathematical formula and a shot in the dark. Rules of thumb are a kind of tool. They help you appraise a problem or situation. They make it easier to consider the subtleties of the topic at hand; they give you a feel for a subject. A rule of thumb is not a joke or a ditty. It is not a Murphy's Law. Murphy says that things will take longer than we think; a rule of thumb says how much longer. While a proverb says that a stitch in time saves nine, a rule of thumb says to allow one inch of yarn for every stitch on a knitting needle."

I've spent a lot of time reading through these over the years. I now subscribe to the Rules of Thumb RSS feed from Parker's site. My new rule of thumb: "One in 25 rules of thumb will be useful to you." YMMV, but I find that a pretty good hit rate.....SOURCE

-- KK

Rules of Thumb

Sample excerpts:

The best way to make money in residential real estate is to buy the worst home on the best street.

The moon covers half a degree of sky.

When digging a grave by hand, haul away 17 wheelbarrow loads of dirt and pile the rest by the hole. You will have just the right amount to backfill.

For marketing purposes, elderly consumers think they are 15 years younger than they actually are.

The price of a telescope increases proportionately to the cube of the lens diameter.

Recovering an unused physical skill takes one month for each year of layoff.

If you walk into a bar where a lot of people wear baseball caps, it's a good place to sell lottery tickets.

Eclipses often come in pairs. A lunar eclipse is followed frequently by a solar eclipse two weeks later, and vice versa.

If the cats aren't sleeping on the radiators, turn down the heat.

One chemical toilet serves 15 employees per week.

It takes two minutes for the sun to drop out of sight once it touches the horizon.

If a woman can walk around during contractions, she is not fully dilated.

When you are working in the vicinity of high voltage, keep 1 foot of distance between you and the power source for each 1,000 volts. For instance, stay 13 feet away from a 13,000 volt power source.